PLATE TECTONICS

PLATE TECTONICS LESSON

Directions:

Print the Plate Tectonics reading comprehension passage and questions (see below).

Students should read the passage silently, then answer the questions.  Teachers may also use the text as part of a classroom lesson plan.

Lesson Excerpt

     In 1910, Alfred Wegener proposed the theory of continental drift.  He noticed that the edges of South America and Africa looked as though they fit together like a large jigsaw puzzle.  He believed that the continents had been joined together at one time but had drifted apart.  He found evidence to prove his theory.  Fossils of plant and animal life matched on the two continents.  Rock layers also matched.  Wegener's theory was first published in 1915.  But he could not answer one question:  How did the continents move?  He thought they were plowing through the ocean crust, moved by tides.  Other scientists knew this could not happen.  Wegener's theory was mostly forgotten.

     In the 1960's, scientists finally found what was missing in Wegener's theory.  Geologist Harry Hess finally could explain how continents moved.  Hess believed that sea-floor spreading is the answer to the mystery of continental drift.

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